There are thousands of people in the U.S. that require the use of powered mobility aids to compensate for their limitations. This number is only going to rise as increasing lifespans lead to an increase in the number of elderly people, especially in the oldest portion of the elderly, where increasing frailty increases the need for mobility aids. These are the same people who have led active lives, and who's efforts to remain active are pushing the limits of the current generation of equipment. The objective of this project is the development of a hybrid power system for electrically powered mobility aids such as wheelchairs and scooters. The power system will consist of a lightweight proton exchange membrane (PEM) fuel cell and a hydrogen storage device as a primary energy supply and a nickel-metal hydride (NiMH) secondary battery for load leveling. It will combine the high energy density of the PEM fuel cell system with the high power delivery density of the NiMH battery to produce a source of electrical power that will weigh less than the lead acid batteries currently used, while storing more energy for a longer range and delivering it at a higher rate for more power. PROPOSED COMMERCIAL APPLICATIONS: Thousands of people suffer spinal injuries every year and require mechanical assistance, to maintain their level of activity. At the same time, the population is aging, with the proportion of people over the age of 65 increasing annually. This creates a substantial market for mobility aids. The equipment currently available is heavy, and has inadequate power. A device that improves the power supplies for this growing market has vast potential.